Aerofoil



pr 0- K. N. PEARSON 1,756,300

AEROFOIL Filed Au 8. 1927 Patented Apr. 29, 1930 KENNETH NOBLE PEARSON, OF NETHERAVQN, snnrrnnron, ENGLAND AEROFOIL Application filed August 8, 1927, Serial No. 211,428, and in Great Britain April 12, 1927.

vThis invention consists of, an aerofoil. of a novel and useful character, adapted for the purpose of controlling the movements of aircraft.

One object of the invention is to enable an aeroplane to be controlled by using the present invention in substitution for the usual ailerons thereby avoiding some of the'disadvantages attendant upon the use of the latter,

as at present designed, particularly the diificult-y of operating them against heavy wind resistance. I

Another object is to stabilize an aeroplane by means of aerofoils in place of ailerons,

1 which will improve the lateral balancing up to and even beyond the usual stalling angle and to simplify the mechanism by. which these aerofoils are operated. I

A' further object is to improve the steering of aircraft by employing my proposed aerofoil as a rudder.

A still further object is to use the proposed aerofoil as an elevator.

Other objects and advantages of the invention may become apparent from the description which follows.

Broadly, the invention when serving the function of improved ailerons, comprises or consists of aerofoils which are mounted so as to be capable of turning horizontally or there abouts through 90 or any other desired angle on a verticalor inclined axis, and each one is so designed aswhen in flight to induce a lifting effect when rotated to one position and a depression when rotatedto the other, these merging into an intermediate neutral position. The turning axis will, of course, be horizontal, when the aerofoil is used as a rudder.

40 In the accompanying drawings, Figs. 1 and 2 illustrate the invention diagrammatically;

Figure 3 represents an aeroplane to which the invention is shown, by way of example only, applied in a particular manner, the rear portion ofthe aeroplane being left out.

Figures 4 and 5 are (on a larger scale) a plan and an elevation respectively of one end of the wing shown inFig. 3, together with the aileron therein illustrated. c

Figure 5 is a view similar to 5 but showing an aeroplane, as illustrated in Figs. 3 to 6, the

a slight Variation in the mounting. Figure 6 is a section on line 6* of Fig. 4.

The principle underlying the invention is exemplified in a simple manner by the arrangement illustrated in Figures 1 and 2 in. each of which an aileron A, illustrated as rectangular-shaped for simplicity, is shown mounted askew upon a' vertical'central axle B, the mounting being a rigid one. The aileron A is, for illustrative purposes, shown merely a flat blade, and the plane in which it lies is essentially not normal to the, axis about which it turns. Let it beassumed that the aileron A is attached to the wing tips of t) aeroplane being regarded as moving through space in the direction opposed to the arrows, from left to right, as viewed in Figs. 1 and 2. Therefore, each of such ailerons presents to the wind a deflecting surface. alternately at the upper and lower faces according to the position to which it has been turned by the partial rotation of the axle B. Figure 1 indicates the wind, (by arrows X X) impinging upon the under surface of the blade A and Figure 2 shows by arrows Y Y the wind blowing upon the upper surface of the blade A.

With the-aileron A occupying the position of Fig. 1, the wing E to which it is attached will become raised, since the wind pressure indicated by the arrows X X exerts a lifting pressure on theaileron A. With the aileron occupying the position of Fig. 2,.0n the other hand, the wing E will become lowered, the wind pressure indicated by the arrows YY exerting a depressing force. In Fig. 1, the aileron A is said to have a positive angle of incidence; in Fig. 2, the angle of incidence is said to be negative.

Referring now to the particular construetion and-design represented in Figures 3 to 6, which illustrate a simple embodiment of my invention, each aileron or aerofoil is shaped roughly circular or oyster-like, as seen in plan with two major axes m of equal length intersecting at right angles to each other, but. not centrally of the figure. The sectional shape upon each of the said axes m is shown streamlined. or cambered upon one face (see 0 Fig. 5) and appr x mately flat or straightmay be considerably varied wit-hout at all cleparting- .-from-,th e spirit-onscspe oft-he in vention. It is important that the positive angle of incidence of the aileron D, in lells' tion to the angle of incidence of the wings E, shall be smallg-whr-le thecorrespond1ngnegative angle of incidence shall belarge. Asas clearly illustrated bygthe full-line; sectional showing of Fig .6, this result is'Very-efiic'iently attainedfiby having the face. approximately straight 'or fiat," within the above definition ofttlie term. The aileron;'D"then presents to thewind a cambered upper surface cand flatlower surface In the opposite, or negative extreme positi'on,.of course, represented by the SGCCl-OII shown 1n-dotted1 linesin Fi'g G, the upper surface. f ofx the aileron D "is shown approximately flat or. straightjand the; lower surfacem cambered The' aerofoils" above described willj be con venientlylocateclat the outer or further ends v h j the'aileron'yD lnoreases as eitheriaile'ron D is moved togive a depressing force- (1. e. moved of.;each"planeor wing E3fone upon each and owing totheir .being rotatably mounted upon a vertical orpart-ly vertical axis, the effort. requircCl'tooperate them willfibe markedl' less than what is required for ailerons of .the

rdinary. nge type.

Anexamplef of th'eir mounting is shownin. res 3, 4, 5 and 5' in-whichfithfe rotary X16.Bf0f the aerofo'il .Dl sls en totbecarrieclf byabracket-Gi H comprised by threeiarms, two of- .whjich fl'radiateflfromythe axis B in;-

a horizontal plane andfare attached at their endsflto the lower edge of theplaneE-gand another arm H'jextendsi in an: inclined di'r.ec-

tion from the axis B to the thick or forward 1 part goffthe planerEg whelie it is fastenedto e t p o th t ier, h rmsG andflIfonnr.

inga threedimensioned/ and, therefore, rigid strncture. The inclined. farm H incidentally a occupies apositionnnearer tothefline of the under fate-10f the aerofoilDlfwhenthe rotary. axle B is; upright as 111E133. 5 {than when. it. is inc -media in 5*:- 7 These are given only as illustrations offiaossibletypes of ,mount-i ings andlthey could be, varied. in. any desired manner;

Appropriate gear f any known. kindran. purpose of operating/ the.

be adapted for the ailerons or aerofoils D.

The meansof operating the ailerons ,tor

aerofoil's. represented by way of example in around" same and suitably "connected .to the control 'stick n. any conven ent manner .as

will be well understood, preferably so as that only one is operated at a time. It is thus possible to move either aileron D without the other, so that movement of the aileron that is situated on that side of the machine which it is required to lower may be effected without movement of the other aileron.

Thetwo extreme positions of the ailerons D are shown in Figures 4 and 6,the full outlineDdenoting the position of maximum lift, with the aileron Dfacingtheopposing wind, andthe dotted outline D the maximum de- .pression, the angle between these positions being 90, though any other suitable angle could be-used if' the shaping of th'e aerofoil were suitably modified. Between these two extreme positions," it .is possible to obtain infinitely smallvariations, there remaining a neutral position wh'en' the forces upon eachface of the aerofoil are mutually balanced A'combination of 'aerofoils, as above described,may be mounted and adapted for use asrele'vators:

VV'hen the aerofoilyabove described, is to be used as :a rudder, its axle will be set horizontally and. any suitable .means of operating such rudder can be employedi The ailerons maybe mounted in such 'a position, and with-'theiraxles 'Bso placecht-hat the a .or clearance between the win E and to theirnegative angle of incidence) and vice versa.

I *cla1m:-'

1. An aileron having two opposed con vexly curved surfaces. adapted to, be subj ected to the action of'wind pressure, a rotatable axle about which the aileronis eccentrically mounted'to. turn, and'meansyfor rotatably adjusting th'eaileron about the. axle to 'pre= sent different portionsof the. surfaces to the wind pressure;each surface having curves of di'ife'r'ent "curvature -1n:-cross-sectional planes substantially at right angles 'to each other,

with the-curve-of greater curvaturetof one surface and the'curveoflesser curvature of thev other surfaceln one of the planes and the curve ofgreater curvature of the-said other surface and the curve of i'lesser'curvature of.

trically'fixed thereto,- the plan shape of said Iaileron or..aerofoil having two major axes intersecting one another at right angles .or the-reabouts, the cross'sectlonal shape upon one of said axes being a figure bounded by a camber.upon a stralght' (or approximately straight) line and upon the other of. said axes a straight (or approximately straight) line Figures '3 to Bfconsis'tsof a groovedpulley ,J f fast upontheaxle Band a wire cord K passedfl connectiiigfth extremities of an inverted camber. and projecting means connected to the wing) about which said axle may rotate and the peripheral edge of the said aileron or aerofoil. r

3. A rotary aileron or aerofoil roughly circular or oyster-like in shape, an axle eccentrically fixed thereto, the plan shape of said aileron or aerofoil having two major-axes intersecting one another at right angles or thereabouts, the cross sectional shape upon one of said axes being a figure bounded by a camber upon a straight (or approximatelystraight) line and upon the other of said axes a straight (or approximately straight) line connecting the extremities of an inverted camber, said axle being located at or near the intersection of the said axes and projecting means (connected to the wing) about which said axle may rotate to vary the distance between the wing tip and the peripheral edge of the said aileron or aerofoil.

l. A rotary aileron or aerofoil roughly circular or oyster-like in shape, anaxle eccentrically fixed thereto, the plan shape of said aileron or aerofoil having two. major axes intersecting one, another at right angles or thereabouts, thecross sectional shape upon one of said axes being a figure bounded by a camber upon a straight (or approximately straight) line and upon the other of said axes straight (or approximately straight) line connecting the extremities of an inverted camber and means connecting said axle with I trically fixed thereto,

the control stick of the aeroplane so that the aileron or aerofoil may beoperated independently of a similar one fitted to the other wing.

5. A rotary aileron or aerofoil roughly circular or oyster-like in shape, an axle eccenthe plan shape of said aileron or aerofoil having two major axes intersecting one another at right angles or thereabouts, the crosssectional shape upon one of said axes being a figure bounded by a camber upon a straight (or approximately straight) line and upon the other of said axes a straight (or approximately'straight) line connecting the extremities of an inverted camber, projecting means (connected to the wing) about which said axle may rotate to vary the distance between the wing tip and the peripheraledge of the said aileron or aerotoil. and means connectingsaid axle with the control stick of the aeroplane so that the aileron or aerofoil may be operated independently of a similar one fitted to the other wing.

6. A rotary aileron or aerofoil roughly circular or oyster-like in shape, an axle eccene trically fixed thereto, the plan shape of said aileron or aerofoil having two major axes intersecting one another at right angles or thereabouts, the cross sectional shape upon one of said axes being a figure bounded by a camber upon a straight (or approximately straight) line and upon the other of said axes a straight (or approximately straight) line connecting the extremities of an inverted camher, said axle being located at or near the intersection of said axes, and means connecting said axle with the control stick of the aeroplane so that the aileron or aerofoil may be operated independently of a similar one fitted to the other wing, projecting means (connected to the wing) about which said axle may rotate being provided to vary the distance between the wing tip and the peripheral edge of the said aileron or aerofoil.

7. A rotary aileron or aerofoil roughly circular or oyster-like in shape, an axle eccentrically fixed thereto, the plan shape of said aileron or aero'foilhaving two major axes intersecting one another at'right angles or thereabouts, the cross. sectional shape upon one of said axes being a figure bounded by a camber upon a straight (or approximately straight) line and upon the other of said axes a straight (or approximately straight) line connecting the extremities ofan inverted camber, said axle being located at or near the intersection of the said axes and means connecting said axle with the control stick of the aeroplane so that the aileron or aerofoil may be operated independently of a similar one fitted to the other wing.

8. A rotary aileron or aerofoil roughly circular or oyster-like in shape, an axle eccentrically fixed thereto, the plan shape of said aileron or aerofoil having two major axes intersecting one another at right angles or thereabouts, the cross sectional shape upon one of said axes being a figure bounded by a camber upon a strai ht (or approximately straight) line and upon the other of said axes a straight (or approximately straight) line connecting the extremities of an inverted camber and projecting means (connected to the wing) about which said axle may rotate to vary the distance between the wing tip and the peripheral edge of the said aileron or aerofoil, and to give a greater negative than positive angle of incidence.

'9. A rotary aileron or 'aerofoil-roughly circular or oyster-like in shape, an axle eccentrically fixed thereto, the plan shape of said aileron or aerofoil having two major axes intersecting one another at right angles or I I thereabouts, the cross sectional shape upon one of said axes being a figure bounded by a camber upon a straight (or approximately straight) line and upon the other of said axes a straight (or approximately straight) line connecting the extremities of an inverted camber, said axle being located at or near the intersection of the said axes andproj ecting 1 means (connected to the wing) about which said axle mayrotate to vary the distance between the wing tip and the peripheral edge of the said aileron or aerofoil and to give'a greater negative than positive angle of incidence. I

In witness whereof Ihave signed this specification.

KENNETH' NOBLE PEARSON. 

